Islington Council may have to repay an estimated 600,000 parking tickets worth tens of millions of pounds because of missing words in the small print.
Almost all tickets issued by Islington since April 2008 may be reviewed because just one parking penalty was overturned due to 'procedural impropriety'.
The penalty in question surrounds a ticket issued to Sai Wong for parking on a single yellow line.
The fine was overturned at the Parking and Traffic Appeals Service (PATAS) after words were allegedly said to be missing from a clause detailing how the fine could be appealed.
The clause in question has been used on all Islington parking tickets since 2008 with the exception being those sent through the post.
Between April 2008 and March 2012 the council issued 701,474 parking tickets, worth up to an estimated £77 million.
Parking campaigner Albert Herbert, who represented Mr Wong thinks this overturned penalty will pave the way for others:
Islington Council says there are no words missing from the small print which was introduced in 2008:
However a PATAS spokesperson said one overturned penalty does not impact on another:
If you think you might be affected you can find help and information on the Parking and Traffic Appeals Service website.